"It's an MLC-based drive family which will complement our existing SLC-based products," said John Fox, head of Hitachi GST's enterprise business in Europe. "SLC is commonly regarded as the higher product. What has happened now is MLC has come to the point where we can offer the same MTBF [mean time between failures] and reliability."

Single-level cell (SLC) flash is generally better for seeking out data
than multi-level cell (MLC) because it is a simpler structure for the drive controller to
navigate. However, it is also more expensive. Hitachi GST uses SLC technology in its Ultrastar SSD400S line of drives.

The Ultrastar SSD400M drives are capable of connecting to devices via a 6Gbps serial attached SCSI (SAS) or 4Gbps Fibre Channel protocols. SAS is a standardised storage protocol used to move data between devices. Multiple SAS devices can be daisy-chained together, making the protocol useful for connecting devices together in large networks.

Fox believes the drives will be used for server and storage virtualisation along with "big data management — metadata, indexing and that sort of thing".

It's an MLC-based drive family which will complement our existing SLC-based products.

– John Fox, Hitachi

The new MLC drives have slower read and write speeds compared with the SLC Ultrastar SSD400S devices, which were released in November. They have higher ceilings on their input/output operations per second (IOPS), making them ideal for reading off large batches of data but less effective at running high-throughput applications.

The drives, available in 400GB and 200GB varieties, are capable of 495MBps read and 385MBps write via 6Gbps SAS, compared with the 535MBps and 500MBps respectively for the SSD400S family.

Each drive has a warranty for five years or to its highest MBTF. The 400GB drive is guaranteed for 7.3PB of random writes over a five-year period — 4TB per day — compared with the 35PB warranty for the SSD400S.

Hitachi expects the drives to begin shipping by September, with batches already sampling with some hardware makers. Pricing was not available.